1. Technical Field
The present invention relates to a sound processing apparatus, a sound processing method and a hearing aid, capable of allowing the user to easily hear the sound of an utterer close to the user by emphasizing the sound of the utterer close to the user relative to the sound of an utterer far away from the user.
2. Background Art
Patent Document 1 is an example of a sound processing apparatus for emphasizing only the sound of an utterer close to the user. According to Patent document 1, near-field sound is emphasized by using the amplitude ratio of the sound input to microphones disposed away from each other by appropriately 50 [cm] to 1 [m] and on the basis of a weighting function that has been calculated in advance so as to correspond to the amplitude ratio. FIG. 30 is a block diagram showing an internal configuration of the sound processing apparatus disclosed in Patent document 1.
In FIG. 30, to a divider 1614, the amplitude value of a microphone 1601A calculated by a first amplitude extractor 1613A and the amplitude value of a microphone 1601B calculated by a second amplitude extractor 1613B are input. Next, the divider 1614 obtains the amplitude ratio between the microphones A and B on the basis of the amplitude value of the microphone 1601A and the amplitude value of the microphone 1601B. A coefficient calculator 1615 calculates a weighting coefficient corresponding to the amplitude ratio calculated by the divider 1614. A near-field sound source separation apparatus 1602 is configured to emphasize near-field sound by using the weighting function that has been calculated in advance according to the amplitude ratio calculated by the coefficient calculator 1615.